Asymmetric MIM type absorbent nanometric structure and method for producing such a structure

Abstract

According to one aspect, the invention relates to an asymmetric MIM type absorbent nanometric structure (1, 1′) intended to receive a wide-band incident light wave the absorption of which is to be optimised within a given spectral band, comprising an absorbent dielectric layer (10) in said spectral band, of subwavelength thickness, arranged between a metal array (11) of subwavelength period and a metal reflector (12). The elements (110, 120) forming the metal array exhibit at least one dimension (w) suitable for forming a plasmonic resonator between the metal array and the metal reflector, under the elements of the array, which plasmonic resonator forms a Fabry-Pérot type longitudinal cavity resonating at a first wavelength of the aimed-for spectral absorption band, and the absorber layer exhibits, between the metal array and the metal reflector, at least one first thickness (ta) suitable for forming at least one first Fabry-Pérot type vertical cavity, resonating at a second wavelength of the aimed-for absorption spectral band.

Description

PRIOR ART[0001]1. Technical Field of the Invention[0002]The present invention relates to an asymmetric MIM type absorbent nanometric structure exhibiting wide-band light absorption, particularly in the visible range, and a method for producing such a structure. More particularly, it is applicable to ultra-thin solar cells.[0003]2. Prior Art[0004]Attempts are constantly being made to reduce the thickness of the active (absorber) layer of solar cells, or photovoltaic cells, in particular to reduce the transit time (time taken by electrons to reach the electrodes, which is generally more than a picosecond) and thus the recombining of photo-induced charges. Attempts are also being made to decrease the thickness of the active layer in order to reduce the costs associated with the material, both the cost of the material itself and the manufacturing cost incurred by processing a greater or smaller quantity of material. Furthermore, limiting the quantity of material enables greater scope fo...

AI Technical Summary

Benefits of technology

[0019]According to a variant embodiment, the structure further comprises a non-absorbing dielectric layer in the aimed-for absorption spectral band, arranged between said absorber layers and the metal array and / or encapsulating the metal array, enabling the thickness between the metal array and the metal reflector to be adjusted.

[0046]For example, the layer made of transparent conductive material is ZnO:Al, less than 50 nm thick. The Applicant has shown an enhancement of the absorption in the near infrared visible spectrum associated with resonances in the layer of transparent conductive material deposited on the metal array.

Problems solved by technology

Furthermore, limiting the quantity of material enables greater scope for plans to use rare materials.

Images